City, who are rooted to the bottom of their group and are without a win in Europe this term, face Ajax at the Etihad Stadium on Tuesday.
Mancini’s men have suffered defeats in Amsterdam and Madrid, while the Eastlands outfit drew 1-1 at home with Borussia Dortmund.
“You should play 100 per cent every game. It’s normal, no? We have three games. We have to think only about Ajax,” said Mancini.
Barring a remarkable turnaround, City are expected to make a premature exit at the group stage for the second successive season.
“We are a good team. We are not ready like the other teams,” added Mancini.
“Chelsea were probably the best team in Europe for 10 years and they won the Champions League after 10 years, probably when they didn’t deserve it.
“They deserved to win the Champions League three or four years before. If we are very good, we are fantastic, we win the next three games, everything can happen.”
• City are hosting Dutch opposition for the third time having twice got the better of Twente. They won 3-2 to secure a 4-3 aggregate success in the 1978-79 Uefa Cup first round, with Brian Kidd, now first-team coach, scoring the second goal.
• Ajax ended a 40-year wait for an away victory over English opponents when beating City’s neighbours United 2-1 in last season’s Europa League round of 32.
• Mario Balotelli’s late penalty equaliser against Dortmund on matchday two means City have still not lost a European home tie since a 1-0 reverse against Midtjylland in the 2008/09 Uefa Cup second qualifying round.
• Ajax’s overall record away to English sides is W2 D4 L4. Their only other success was a 1-0 victory at Arsenal in the 1971-72 European Champion Clubs’ Cup quarter-finals.
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